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About the polymorphism of [Li(C(4)H(8)O)(3)]I: crystal structures of trigonal and tetragonal polymorphs
Two new trigonal and tetragonal polymorphs of the title compound, iodidotris(tetrahydrofuran-κO)lithium, are presented, which both include the isolated ion pair Li(THF)(3) (+)·I(−). One Li—I ion contact and three tetrahydrofuran (THF) molecules complete the tetrahedral coordination of the l...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
International Union of Crystallography
2014
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4257418/ https://www.ncbi.nlm.nih.gov/pubmed/25552991 http://dx.doi.org/10.1107/S160053681402529X |
Sumario: | Two new trigonal and tetragonal polymorphs of the title compound, iodidotris(tetrahydrofuran-κO)lithium, are presented, which both include the isolated ion pair Li(THF)(3) (+)·I(−). One Li—I ion contact and three tetrahydrofuran (THF) molecules complete the tetrahedral coordination of the lithium cation. The three-dimensional arrangement in the two polymorphs differs notably. In the trigonal structure, the ion pair is located on a threefold rotation axis of space group P-3 and only one THF molecule is present in the asymmetric unit. In the crystal, strands of ion pairs parallel to [001] are observed with an eclipsed conformation of the THF molecules relative to the Li⋯I axis of two adjacent ion pairs. In contrast, the tetragonal polymorph shows a much larger unit cell in which all atoms are located on general positions of the space group I4(1) cd. The resulting three-dimensional arrangement shows helical chains of ion pairs parallel to [001]. Apart from van der Waals contacts, no remarkable intermolecular forces are present between the isolated ion pairs in both structures. |
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